Numerous devices exist for the retrieval of objects that have become submerged underwater; however, most of the devices used for retrieving golf balls are affixed to rods or poles, which by necessity of limitations on length can only retrieve golf balls located at minimal distances from the operator of the device. Examples of such devices are U.S. Pat. No. 4,021,068 to Piazza and U.S. Pat. No. 4,549,758 to Meshulam. Several of the existing underwater retrieval devices must be dragged along the bottom of the body of water after the object has been captured, and therefore cannot function reliably under different conditions. Such devices are exemplified by U.S. Pat. No. 3,756,644 to Rydberg and U.S. Pat. No. 3,276,807 to Ward.
U.S. Pat. No. 3,926,464 to Alexander discloses a golf ball retrieval device which floats, but which can only capture the golf balls at a fixed depth, due to the fixed arrangement of the capture nets with respect to the floating portion of the device.
Two other marine salvage devices of general interest are U.S. Pat. No. 2,355,086 to Lang and U.S. Pat. No. 3,647,253 to Hettinger et al. The '086 patent to Lang employs a casing with a threaded shaft located inside the casing, the shaft being attached to a pair of jaws used to capture the object to be retrieved. This device, however, does not float and must be lowered into the water directly above the object to be retrieved.
The invention disclosed by the '253 patent to Hettinger et al is not submersible and is capable of retrieving only those objects which are floating on the surface of the water. In addition, the "expandable bladder" in the '253 patent functions only as a gripping means, and provides no flotation function.
U.S. Pat. No. 4,410,210 to de Sivry et al employs an inflatable bladder to grip the object to be picked up, but not for flotation purposes. Furthermore, there is no indication that such a device would be used for underwater retrieval.